- Joined
- Jun 9, 2008
- Messages
- 1,922
Stellite has never been used to tip the followers, Delcrome has which was produced by the firm called Stellite way back who made various cobalt and iron hard faced materials and alloys and no surprise a material actually called Stellite. Current supplier of Delcrome is Delero in Europe, a subsidiary of a US company. Stellite and Delcrome are two very different materials, one iron based, one cobalt based, they can suit the same function but at different temperatures and Stellite has a better resistance to corrosion obviously. The other major major difference is cost, Cobalt is traded on the metal markets in lbs, not tonnes. Deloro also supply and apply coatings, and don't seem to need to advise coating Delcrome.
The answer to the cam failure is in post 1 on page 1 - the fact that the coated followers were not affected is typical of coating application. It will provide a very good sliding surface, but not one that can sustain impact as well - yes, it hard, but that is a function of the coating being able to reduce friction, the hardness of a coating when used on a cam is not what is being asked for. ask those that coat why this is and they should tell you, not sell to you - ever wondered what happens to the substrate under the interface of the coating when being applied. No doubt some can work out why the Delcrome will take a coating and survive and the cam does not. If you have a cam in constant contact with the cam follower then a coating would be ideal. The same problem has been around for ages in the grinding industry when grinding hardened bearing surfaces, but they will avoid it.
Beehive springs - excellent piece of kit, but you just can't use any beehive spring. The move from nested springs to single spring is the clue - ever wondered why there are two springs, not one when Norton could have used one, the second spring has another function other than get the poundage right to control the valve correctly. The low revivng engines we use are not even a challenge to spring makers these days.
It is also no secret who manufacturers these chill cast cams, do you honestly think that they buy just 50 blanks and grind them, no, more thousands at a time. Considering this is about one type of chilled cam issue, then further questions other than chill cast need to be queried. Considering the number of cams sold, inc PW3 that are fitted by many engine builders worldwide and home mechanics (some of whom are well over 26K miles on there PW3's) would quite clearly indicate that there is not an issue with the chill cast cams. Those that retail PW3 cams, maybe a surprise to some, but actual sell more than one every now and then. If there was an issue with chill cast, do you honestly think that any of them would carny on using it, no it would be substituted, so make your own minds up.
Coatings are excellent when used in the correct place, those that apply coatings should advise accordingly on application and suitability of base material and its pre-coat state and post coat state.
The answer to the cam failure is in post 1 on page 1 - the fact that the coated followers were not affected is typical of coating application. It will provide a very good sliding surface, but not one that can sustain impact as well - yes, it hard, but that is a function of the coating being able to reduce friction, the hardness of a coating when used on a cam is not what is being asked for. ask those that coat why this is and they should tell you, not sell to you - ever wondered what happens to the substrate under the interface of the coating when being applied. No doubt some can work out why the Delcrome will take a coating and survive and the cam does not. If you have a cam in constant contact with the cam follower then a coating would be ideal. The same problem has been around for ages in the grinding industry when grinding hardened bearing surfaces, but they will avoid it.
Beehive springs - excellent piece of kit, but you just can't use any beehive spring. The move from nested springs to single spring is the clue - ever wondered why there are two springs, not one when Norton could have used one, the second spring has another function other than get the poundage right to control the valve correctly. The low revivng engines we use are not even a challenge to spring makers these days.
It is also no secret who manufacturers these chill cast cams, do you honestly think that they buy just 50 blanks and grind them, no, more thousands at a time. Considering this is about one type of chilled cam issue, then further questions other than chill cast need to be queried. Considering the number of cams sold, inc PW3 that are fitted by many engine builders worldwide and home mechanics (some of whom are well over 26K miles on there PW3's) would quite clearly indicate that there is not an issue with the chill cast cams. Those that retail PW3 cams, maybe a surprise to some, but actual sell more than one every now and then. If there was an issue with chill cast, do you honestly think that any of them would carny on using it, no it would be substituted, so make your own minds up.
Coatings are excellent when used in the correct place, those that apply coatings should advise accordingly on application and suitability of base material and its pre-coat state and post coat state.